Structure Diagram#
set（集合）#
An internally automatically ordered container without duplicate elements
#include <set>
set<int> name;
set<double> name;
set<char> name;
set<struct node> name;
set<set<int> > name;//Note: there should be a space between > >
set<int> arr[10];
Accessing Elements in a set Container#
set can only be accessed through iterators (except for vector and string, all other STL containers do not support the access method *(it+i)):
set<int>::iterator it;
set<char>::iterator it;
for (set<int>::iterator it = st.begin(); it != st.end(); it++)
{
cout << *it << endl;
}
Common Functions#
insert(value)#
st.insert('C');
find(value)#
find(value) returns the iterator corresponding to the value in the set, which is the pointer (address) of the value
cout << *(st.find(2)) << endl;
erase(it)#
st.erase(st.find(100)); //find 100 using find() function, then erase it using erase()
erase(iteratorBegin , iteratorEnd)#
Left-closed and right-open
st.erase(it, st.end());
size()#
cout << st.size() << endl;
vector（矢量）#
Variable-length array
#include <vector>
vector<int> name;
vector<double> name;
vector<char> name;
vector<struct node> name;
vector<vector<int> > name;//Note: there should be a space between > >
In a two-dimensional array, its one-dimensional form is the address. For example:
int arr[3][2];//Define a 3-row 2-column address
cout<<arr[0]<<endl; //Output the address of the first row of arr
output:
0x61fe00 //The address of the first row of arr
Accessing Elements in a vector Container#
(1) Accessing by Subscript
cout<<vi[0]<<endl;
(2) Accessing by Iterator
An iterator can be understood as a pointer
vector<type>::iterator variableName;
vector<int>::iterator it;
vector<double>::iterator it;
vector<int>::iterator it=v.begin();
for (int i = 0; i < v.size(); i++)
{
cout<<it[i]<<" ";
}
vector<int>::iterator it=v.begin();
for (int i = 0; i < v.size(); i++)
{
cout<<*(it+i)<<" ";
}
//The iterator of vector does not support the writing of it<v.end(), so the loop condition can only be it!=v.end()
for (vector<int>::iterator it=v.begin(); it!=v.end();it++)
{
cout<<*it<<" ";
}
Analysis of Common Functions in vector#
(1) push_back(item)#
v.push_back(i);
(2) void pop_back()#
v.push_back(i);
(3) size()#
cout<<v.size()<<endl;
(4) clear()#
v.clear();
(5) insert()#
insert(__position,__x);
v.insert(v.begin()+2,-1); //Insert -1 at the position of v[2]
(6) erase() Left-closed and right-open#
erase(__position); //Delete an element
v.erase(v.begin()+3);
erase(__positionBegin,__positionEnd);//Delete elements within a range
v.erase(v.begin()+1,v.begin()+4);